Zenza Bronica ETRS - shutter does not fire but mirror reacts

Hi Bronica Fans,

I just bought a Zenza Bronica ETRS with the 75mm f2.8 lens.
At first glance all seemed to work fine (just testing without film or even without the film back attached), but setting the exposure time to 1 sec I can see through the lens, that the shutter does not open when pressing the shutter release button on the body.
The mirror reacts as normal flipping up.
When it misfires (sometimes it does fire), when I hold the lens base at the mount and try to rotate it a little bit, there is a very small play. After moving it 2-3 times back and forth, the shutter enganges, which I can see through the lens, opening to the desired aperture and closing after 1 second.

Has anybody experienced the same problem with a bronica lens? Is it mechanical or electronical problem with the 6 contacts?

Cheers - Artur

If wiggling the lens mount results in the shutter firing, it definitely sounds like an electrical contact issue. Not unheard off with the ETR series (and any other similar lens mount/system for that matter). Give them a clean.

I'd also check the battery, probably best to replace it with a new one if there's any doubt.

An ETRS lens shutter is mechanically triggered, but electronically timed. It's a little unclear to me if you were saying that it misfires at the 1 sec setting only, or that it misfires at any shutter setting. With an ETR or ETRS, even without the battery the camera should be able to fire the shutter at 1/500 sec (I don't know if this is true for the ETRSi). You can watch this in action by shining a light through from the open back and firing the shutter - lens closes shutter, mirror flips up, shutter opens for an instant and then closes again.

Slop in the lens mount could cause problems for both the mechanical and electronic contacts. When you mount the lens (with both lens and body cocked), turning the lens counter-clockwise, the mechanical shutter cocking pins ride over a spring loaded beveled metal ridge in the camera next to the pin with the green dot, so that the lens pin is engaged. (This spring loaded ridge is like the latch bolt of a door, and is retracted by the lens release button.)

When the camera is fired, this green-dot and ridge body assembly moves upward, carrying the lens pin with it to fire the shutter. When the camera is cocked, the body assembly moves down to cock the lens. If the lens mount is really sloppy and the lens pin doesn't ride over the metal ridge, it might let you cock the lens shutter but not fire it. Try turning the lens further counterclockwise as viewed from the front when you mount it.

On the other hand, if the electronic contacts are not making contact, it's possible that the lens would fire and only stay open for 1/500 sec, not the expected 1 sec. Further testing is needed to understand when and how it is misfiring.

Ordinarily the ETRS(i) will not release its shutter at all unless

1. the dark slide is removed from film magazine, and
2. film has been advanced to a fresh unexposed frame (or the multiexposure lever if one is available, is active)
3. and the reflex mirror has flipped up fully (or the mirror is locked up, if the body has mirror lockup lever)

reddesert said:

An ETRS lens shutter is mechanically triggered, but electronically timed. It's a little unclear to me if you were saying that it misfires at the 1 sec setting only, or that it misfires at any shutter setting. With an ETR or ETRS, even without the battery the camera should be able to fire the shutter at 1/500 sec (I don't know if this is true for the ETRSi). You can watch this in action by shining a light through from the open back and firing the shutter - lens closes shutter, mirror flips up, shutter opens for an instant and then closes again.

Click to expand...

It happens in all longer exposure times, which I can observe with my eye. The shutter is closed, the mirror flips up, but the shutter does not move.

reddesert said:

Slop in the lens mount could cause problems for both the mechanical and electronic contacts. When you mount the lens (with both lens and body cocked), turning the lens counter-clockwise, the mechanical shutter cocking pins ride over a spring loaded beveled metal ridge in the camera next to the pin with the green dot, so that the lens pin is engaged. (This spring loaded ridge is like the latch bolt of a door, and is retracted by the lens release button.)

Click to expand...

The camera pin is in the correct position between the body pin and the other one I checked this after removing the focus screen and cocking the camera (mirror fully down).

reddesert said:

When the camera is fired, this green-dot and ridge body assembly moves upward, carrying the lens pin with it to fire the shutter. When the camera is cocked, the body assembly moves down to cock the lens. If the lens mount is really sloppy and the lens pin doesn't ride over the metal ridge, it might let you cock the lens shutter but not fire it. Try turning the lens further counterclockwise as viewed from the front when you mount it.

Click to expand...

I tried turning it as far counterclockwize as possible off course

reddesert said:

On the other hand, if the electronic contacts are not making contact, it's possible that the lens would fire and only stay open for 1/500 sec, not the expected 1 sec. Further testing is needed to understand when and how it is misfiring.

Click to expand...

It certainly does not fire at all, because it engages only if I wiggle the lens mount after release

wiltw said:

Ordinarily the ETRS(i) will not release its shutter at all unless

1. the dark slide is removed from film magazine, and
2. film has been advanced to a fresh unexposed frame (or the multiexposure lever if one is available, is active)
3. and the reflex mirror has flipped up fully (or the mirror is locked up, if the body has mirror lockup lever)

Click to expand...

All conditions are met

benderscameracorner said:

If wiggling the lens mount results in the shutter firing, it definitely sounds like an electrical contact issue. Not unheard off with the ETR series (and any other similar lens mount/system for that matter). Give them a clean.

I'd also check the battery, probably best to replace it with a new one if there's any doubt.

Click to expand...

I already cleaned the pins on the lens and the contact balls in the body mount moderately with isopropyl alcohol on a qtip. I also inserted a fresh battery. It did not help.
Maybe the balls in the body mount stuck because of old grease or the springs underneath (suppose there are some) are week?

Go visit this post by @lxdude and, if you read farther down the page, you'll see I had good luck with his suggestion. You will need to take the rear of the lens off and getting those screws to release might be difficult. What's happening to your lens is almost certainly the same that happened to mine.

artur2000 said:

I already cleaned the pins on the lens and the contact balls in the body mount moderately with isopropyl alcohol on a qtip. I also inserted a fresh battery. It did not help.
Maybe the balls in the body mount stuck because of old grease or the springs underneath (suppose there are some) are week?

Click to expand...

The electrical pins have nothing to do with SHUTTER OPEN, that is entirely caused by the rotational lever of the body which releases after the reflex mirror rises sufficiently. Even in the absence of any electrical signal (dead battery in body) the shutter should open and then close 1/500 sec. later.

You stated, " The shutter is closed, the mirror flips up, but the shutter does not move." I once had purchased a used film back for use with a newly-purchased body, and the shutter would inconsistently fail to fire with only that back...I sent body and back to GMI Photographic (Bronica distributor before Tamron purchase) and it turned out that the film-advanced interlock pin of the back projected too far into the body, which caused the reflex mirror to fail to rise all the way, so the shutter would not open. GMI shortened the pin in the back, returned the items to me fully functioning.
The shutter failure to open should be irrelevant to the time set on the shutter, as that only effects the close of the shutter (timed, or always 1/500)

wiltw said:

The electrical pins have nothing to do with SHUTTER OPEN, that is entirely caused by the rotational lever of the body which releases after the reflex mirror rises sufficiently. Even in the absence of any electrical signal (dead battery in body) the shutter should open and then close 1/500 sec. later.

You stated, " The shutter is closed, the mirror flips up, but the shutter does not move." I once had purchased a used film back for use with a newly-purchased body, and the shutter would inconsistently fail to fire with only that back...I sent body and back to GMI Photographic (Bronica distributor before Tamron purchase) and it turned out that the film-advanced interlock pin of the back projected too far into the body, which caused the reflex mirror to fail to rise all the way, so the shutter would not open. GMI shortened the pin in the back, returned the items to me fully functioning.
The shutter failure to open should be irrelevant to the time set on the shutter, as that only effects the close of the shutter (timed, or always 1/500)

Click to expand...

Thank you for this insight. In my case (ETRS), I tested the shutter release even without any back attached, so I was able to look through the back of the body and the lens. The shutter didn't even flicker. So I suppose, its somewhat different here. But Thank You for pointing out one possible direction.

Don_ih said:

Go visit this post by @lxdude and, if you read farther down the page, you'll see I had good luck with his suggestion. You will need to take the rear of the lens off and getting those screws to release might be difficult. What's happening to your lens is almost certainly the same that happened to mine.

Click to expand...

Thank You. It seems to be a mechanical issue then, in line with what @wiltw suggested above. I will come back with the results of the repair.

An update on this issue is surprising. I sent the camera back to the seller and got a refund. He wanted to service the camera, but after 2 days siting on his desk, the problem disappeared.
Our suspition is, that the camera must have faced some low temperatures for a longer time period during delivery and the grease thickened enough to prevent correct function.
Now, after longer time in room temperature, the grease is fluid enough again.

artur2000 said:

Thank You. It seems to be a mechanical issue then, in line with what @wiltw suggested above. I will come back with the results of the repair.

Click to expand...

It was a mechanical issue and most likely inside the lens (shutter).

It would be better if the owner tried with a different lens.